Charge in a Si,Al,Si oxide

[pmignon]

Dear,

I performed a VASP calculation on a layer of Si Al Si oxide with substitution of one Al by Mg and insertion of Na+. My system is that:
H 8 O 48 Na 1 Mg 1 Al 7 Si 16

I did an SCF with PREC = high.
And followed the instructions taking into account the core charge : summing AECCAR0 AECCAR2 and launch bader CHGCAR -ref CHGCAR_sum.
Everthing seems to work fine, but I get some strange results: the total number of electrons is said to be 390 but it should be 730. And the charge on the atoms seems strange to me (ex oxygens should have a charge greater than 8 ... , ...).
Here is the ACF.dat file:

# X Y Z CHARGE MIN DIST ATOMIC VOL
--------------------------------------------------------------------------------
1 1.1729 8.3592 8.1048 0.3777 0.0545 2.1210
2 1.3006 3.5059 7.7122 0.3550 0.0681 2.0769
3 5.6938 0.7341 7.9837 0.3119 0.0580 1.9831
4 5.6690 5.8197 8.0402 0.3626 0.0583 2.1155
5 3.9819 10.0225 10.4728 0.3448 0.0209 2.1596
6 8.5420 2.2844 10.3428 0.3485 0.0870 2.1108
7 8.3769 7.4625 10.5797 0.3606 0.0496 2.1423
8 3.9638 4.9913 10.3737 0.3663 0.0783 2.2045
9 7.8467 9.9784 12.7425 7.5769 0.7991 62.4583
10 3.1558 9.5192 10.3594 7.4797 0.6785 15.1009
11 6.4848 9.5273 10.4579 7.6053 0.9312 13.8788
12 0.3386 9.8356 10.4569 7.6138 0.9326 13.8040
13 3.7150 7.5503 5.9938 7.5801 0.7972 67.5394
14 4.2830 10.1472 6.1784 7.5810 0.8112 42.5804
15 6.2118 8.3833 5.9938 7.5795 0.8083 66.9619
16 8.1180 10.2042 6.0068 7.5751 0.8113 66.9887
17 8.7580 7.6585 6.2453 7.5834 0.8002 40.0441
18 1.9743 8.8376 8.3721 7.4493 0.6678 14.6076
19 7.5102 8.8961 8.2798 7.5959 0.8725 13.5652
20 4.7816 8.5051 8.2617 7.6181 0.9482 13.8056
21 5.7965 3.1683 12.7979 7.5892 0.8150 59.1459
22 5.3549 0.5210 12.5947 7.5846 0.8007 45.9266
23 1.7421 0.6872 5.9617 7.5791 0.8081 71.5687
24 6.4832 1.1609 8.3548 7.5117 0.6761 14.9756
25 3.0661 1.0645 8.2437 7.5953 0.9296 14.3027
26 0.3392 0.7459 8.2745 7.6001 0.8677 13.6614
27 3.4007 2.2630 12.7067 7.6025 0.8270 43.5243
28 1.4159 0.5186 12.7889 7.5729 0.8083 70.0914
29 0.9757 3.1283 12.5536 7.5948 0.8073 39.7960
30 7.6742 1.8392 10.3222 7.4764 0.7240 15.2395
31 1.9513 1.7203 10.4721 7.5866 0.9171 14.2830
32 4.9265 2.1210 10.4856 7.5903 0.9035 14.4382
33 7.8507 4.8105 12.7547 7.5788 0.8028 66.2142
34 5.8747 8.2552 12.7388 7.5741 0.7956 63.0374
35 5.3402 5.6674 12.5367 7.6056 0.8242 33.6811
36 3.1172 4.5193 10.4810 7.4560 0.6848 15.2017
37 6.5167 4.3742 10.4635 7.6095 0.9263 13.8032
38 0.3423 4.7616 10.4565 7.6175 0.9329 13.8670
39 1.7474 5.8391 6.0368 7.5833 0.8091 62.4661
40 3.7397 2.4195 6.0342 7.5823 0.8181 60.0631
41 4.2911 5.0171 6.2405 7.5851 0.7980 39.5233
42 6.4389 6.3037 8.3833 7.4622 0.6518 14.7061
43 3.1086 6.3370 8.3002 7.6010 0.8939 13.4888
44 0.3260 6.0135 8.3091 7.5965 0.9039 13.5329
45 3.4003 7.3196 12.7430 7.5919 0.8334 55.1182
46 1.4312 5.6777 12.7382 7.5905 0.8079 47.5008
47 0.8831 8.2258 12.5414 7.5841 0.8027 41.3339
48 7.5610 6.9735 10.3733 7.4616 0.6894 14.9252
49 2.0190 6.9841 10.4402 7.5966 0.8564 13.5448
50 4.7965 7.3195 10.4459 7.6142 0.8535 13.6929
51 6.2419 3.2620 5.9765 7.5812 0.8119 71.3544
52 8.1528 5.0593 6.0314 7.5787 0.7994 64.3216
53 8.7918 2.5104 6.2956 7.5841 0.8208 37.2376
54 1.9943 3.8515 8.2921 7.4660 0.6658 15.5114
55 7.5650 3.7851 8.2953 7.5928 0.8889 13.5582
56 4.9099 3.4072 8.2692 7.5921 0.8619 14.1885
57 3.3903 4.5269 13.3306 6.0956 0.9165 69.7503
58 3.2994 2.7760 9.3476 0.3325 0.7143 4.6328
59 3.2913 7.9298 9.3345 0.5165 0.6389 3.4738
60 6.2615 7.9157 9.3413 0.5171 0.6360 3.5117
61 7.7599 0.2061 9.3440 0.5229 0.6452 3.5274
62 1.8340 0.1810 9.3376 0.5175 0.6452 3.4699
63 7.7548 5.3722 9.3485 0.5155 0.6461 3.4998
64 1.8387 5.3313 9.3475 0.5231 0.6545 3.5227
65 6.3012 2.7574 9.3494 0.5144 0.6480 3.4541
66 6.3974 9.6607 12.1000 0.8566 0.5305 3.3895
67 4.7278 8.6503 6.6046 0.8450 0.5249 3.3572
68 0.4130 9.7199 12.0960 0.8525 0.5349 3.3265
69 7.6476 8.7780 6.6305 0.8695 0.5387 3.4337
70 4.9062 1.9899 12.0902 0.8611 0.5244 3.3501
71 3.1984 0.9997 6.6235 0.8500 0.5420 3.3864
72 1.9291 1.8838 12.0772 0.8570 0.5319 3.3675
73 0.2914 0.9694 6.6389 0.8615 0.5284 3.4084
74 6.4057 4.5067 12.0856 0.8495 0.5259 3.3446
75 4.8846 7.1726 12.0750 0.8509 0.5229 3.3462
76 3.2134 6.1502 6.6557 0.8591 0.5403 3.3966
77 4.7702 3.5135 6.6483 0.8580 0.5228 3.3060
78 1.9331 7.0962 12.0664 0.8668 0.5500 3.3714
79 0.4085 4.5750 12.0800 0.8484 0.5496 3.3604
80 7.6688 3.6333 6.6509 0.8655 0.5303 3.3998
81 0.2790 6.1456 6.6592 0.8591 0.5318 3.3785
--------------------------------------------------------------------------------
NUMBER OF ELECTRONS: 390.00002



Do you have any advises ??
Thanks in advance,
PIerre.

[pmignon]

Sorry I forgot: The PAW I used are :

TITEL = PAW_PBE H 15Jun2001
TITEL = PAW_PBE O 08Apr2002
TITEL = PAW_PBE Na_pv 05Jan2001
TITEL = PAW_PBE Mg 05Jan2001
TITEL = PAW_PBE Al 04Jan2001
TITEL = PAW_PBE Si 05Jan2001


Thank you
Pierre.

[graeme]

The analysis is done on the valance density. There are 390 valance electrons so your sum looks fine. There are 6 valance electrons for O, so your charges on those atoms also looks fine. The total density is used to do the partitioning, but the sum over the Bader volumes is done for valance electrons only.